简介：Theperformanceofmassivemultiple-inputmultiple-output(MIMO)systemislimitedbypilotcontamination.Toreducethepilotcontamination,uplinkanddownlinkprecodingalgorithmsareputforwardbasedoninterferencealignmentcriterion.Intheuplinkreceivingprocessing,thetargetfunctionalignsthepilotcontaminationandtheinterferencesignalstothesamenullspaceandacquiresthemaximalspacedegreeofthedesiredsignals.Theuplinkreceivingprecodingmatrixissolvedonmaximalsignaltointerferenceplusnoiseratio(SINR)criterionconsideringtheimpactofthepilotcontaminationonchannelestimations.Theuplinkreceivingprecodingmatrixisusedasthedownlinktransmittingprecodingmatrix.Exploitingthechannelreciprocity,itisprovedthat,iftheuplinkreceivingprecodingmatrixachievesmaximalSINR,theidenticalprecodingmatrixcanbeusedinthedownlinktransmissionandacquiresmaximalsignaltoleakageplusnoiseratio(SLNR).Simulationsshowthatthespectrumefficiencyoftheproposedalgorithmcanreachabout1.5timeshigherthanthatofpopularmatchedfiltering(MF)precodingalgorithm,andabout1.1timeshigherthanmulti-cellminimummeansquareerror(MMSE)precodingalgorithm.Theperformanceoftheproposedalgorithmcanbeimprovedapproximatelylinearlywiththeincreasingofthenumberofantennas.

简介：以多载频矩形脉冲信号为发射信号,建立了机载分布式相干MIMO雷达的杂渡模型；给出了经典的杂波功率谱估计方法和杂波自由度估计规则；仿真分析了多载频频率步进和不同误差条件下的最小方差（MV,minimumvariance）杂波谱和杂波特征谱.仿真及分析结果表明：机载分布式相干MIMO雷达的杂波具有空时二维斜对角分布特性；杂波起伏、载机偏航均会使杂波谱展宽及杂波自由度增大；多载频频率步进的增长导致杂波去相关.

简介：Theoptimalestimationperformanceoftargetparametersisstudied.First,thegeneralformofCramer-Raobound(CRB)forjointestimationoftargetlocationandvelocityisderivedforcoherentmultipleinputmultipleoutput(MIMO)radars.TogainsomeinsightintothebehavioroftheCRB,theCRBwithasetofgivenorthogonalwaveformsisstudiedasaspecificcase.Second,amaximumlikelihood(ML)estimationalgorithmisproposed.Themeansquareerror(MSE)oftheMLestimationoftargetlocationandvelocityisobtainedbyMonteCarlosimulationanditapproachesCRBinthehighsignal-to-noiseratio(SNR)region.

简介：针对以往的AdHoc网络的缺陷，提出了一种基于MIMO技术和“双环”技术的AdHoc网络路由协议方案。在MIMO技术、“双环”技术的支持下，新的AdHoc网络路由协议中采用了分集链路与复用链路，发挥了DZR协议与ZRP协议的优势，以OPNET仿真工具为平台，从而实现了新AdHoc网络路由协议的最优化。

简介：Two-dimensional(2D)multiple-inputmultiple-output(MIMO)iscurrentlyconcentratedonpropagationinhorizontalplane,buttheimpactofelevationangleisnotconsidered.However,duetothethree-dimensional(3D)characteroftherealMIMOchannel,2DMIMOcannotachievetheoptimalsystemthroughput.Amultiple-userMIMO(MU-MIMO)userpairingschemewasproposed,inwhichtheverticaldimensionwastakenintoconsideration.Intheproposedscheme,a3DcodebookbasedonfulldimensionMIMOchannelwasdesigned;thentwo3DMU-MIMOuser'spairingschemesareproposedcombiningtheproposedjointandseparate3Dcodebook.Simulationevaluatestheproposed3Dcodebookaideduserpairingschemeandcompareswiththeprevious2DMU-MIMOuserpairingtechnology.Owingtotheadditionalspatialdegreeoffreedominverticaldimension,theproposed3DMU-MIMOuserpairingschemescaneffectivelyimprovetheoverallsystemperformance.